Kiln Pointers

Place the dichroic glass onto a dark background. Then touch a paper clip to the glass surface and look at the shadow.

CONTENTS

Identifying the Coated Side of Dichroic Glass

Recent Q&As: Enameling safety; does replacing only one element adversely affect the other elements?

A Kiln Story: The Mystery of the Burned Out Element

Memorable Quote

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IDENTIFYING THE COATED SIDE OF DICHROIC GLASS

Dichroic glass, which helped popularize glass fusing, has a decorative metallic coating. Dichroic glass is available with a transparent or opaque glass base. On a transparent base, some light dichroic colors look the same on both sides of the glass. Finding the coated side is all but impossible--until you know the following trick.

Place the dichroic glass over a dark background. Then adjust your viewing angle until the surface reflection overpowers the dark background.

Touch the glass surface with a paper clip. You will see the paper clip reflected in the dichroic coating. Does the reflection meet the paper clip, or is there a gap between the paper clip and its reflection?

On the coated side of the glass, the paper clip will touch its reflection. On the base side of the glass, a gap will separate the paper clip from its reflection. The gap equals the thickness of the glass.

Why do you need to know which side is coated? Because when fused with the coated side up, the dichroic surface has a metallic sheen. When fused with the coated side down, the same dichroic glass sparkles like glitter and sometimes changes colors when viewed from different angles. The more you know about dichroic glass, the greater the range of effects you can achieve.

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RECENT Q&As

Q. I have a Paragon SC-2BW (ceramic fiber kiln with bead door). I am a little confused. The manual says, “The heating element under power is dangerous. Do not touch the element with anything! Turn the kiln switch off before inserting an enamelling fork into the firing chamber.” By turning the kiln switch off, I will reduce the temperature too much, and I would have to re-programme the kiln. With a class full of students all wanting to fire their pieces, this would not work. Can I insert and remove a trivet full of work using a firing fork while the kiln is holding its temperature and switched on?

A. I suggest that you turn off the switch on the front of the kiln before you open the door to insert the enameling fork. Turn the switch back on after you close the door. The switch will be off for only a few seconds. After you turn the switch back on, the display will show PF and the kiln temperature. Ignore the PF, which indicates a power failure. The kiln will continue to fire normally. Since the elements are off for only a few seconds, the temperature should drop by only a few degrees. Most of the temperature drop is due to opening the door.

Q. On a kiln with several elements, does replacing just one element cause the others to burn out more quickly?

A. Replacing only one element does not adversely affect the other elements in the kiln. If an element burns out due to contact with foreign materials, replace only that element. If an element burns out near the end of the expected life of a set of elements, then replace all the elements.

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A KILN STORY: THE MYSTERY OF THE BURNED OUT ELEMENT

A customer owned a Janus-1613 kiln, which has elements in the walls and lid. She ordered new side elements, because the center element would not fire. She installed the center element and test-fired the kiln to 600 degrees F (315 degrees C). The center element still wouldn’t fire. “We were sure to mark the appropriate wire to its corresponding element,” the customer said. “Everthing was screwed back tightly. The other two elements are heating up properly.”

It turned out that the center element didn’t need to be replaced after all. It wouldn’t fire because of a faulty relay. “We put in a new relay, and all is finally good now,” the customer reported.

Before you replace an element, check it with an ohmmeter, which will indicate whether the element is broken. The problem could be as simple as a disconnected wire.

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MEMORABLE QUOTE

“Have I made an impact with my craft? Will it last through time? Do I work hard enough? That is what haunts me. These are the questions that come as you age.” --Mel Jacobson, potter (79 years old)

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Two weeks ago I attended an Open House at Ed Hoy’s International, a glass distributor near Chicago. On the flight to Chicago, I sat next to an off-duty American Airlines flight attendant named Deborah. We talked during the entire flight, oblivious of time. Some of the stories about her career made me convulse with laughter. Others were touching. Deborah said that of all the celebrities she has met during her 45 years of flying with American, the most memorable was Omar Bradley, a retired general in 1979. I know the late Ed Hoy would have enjoyed talking to Deborah. He served indirectly under Bradley.

The Ed Hoy’s warehouse bustled with excited customers who wandered past rows of wooden bins of glass. Even in the subdued lighting, sheets of dichroic glass looked like dazzling rainbows. Pickup trucks inched up the driveway into the warehouse, where employees loaded crates of glass. I enjoy the energy of happy, creative people.